<html lang="en"> <head> <title>VAX-operands - Using as</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="Using as"> <meta name="generator" content="makeinfo 4.7"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Vax_002dDependent.html#Vax_002dDependent" title="Vax-Dependent"> <link rel="prev" href="VAX_002dbranch.html#VAX_002dbranch" title="VAX-branch"> <link rel="next" href="VAX_002dno.html#VAX_002dno" title="VAX-no"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <!-- This file documents the GNU Assembler "as". Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002, 2006, 2007 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. man end--> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family: serif; font-weight: normal; } --></style> </head> <body> <div class="node"> <p> <a name="VAX_002doperands"></a>Next: <a rel="next" accesskey="n" href="VAX_002dno.html#VAX_002dno">VAX-no</a>, Previous: <a rel="previous" accesskey="p" href="VAX_002dbranch.html#VAX_002dbranch">VAX-branch</a>, Up: <a rel="up" accesskey="u" href="Vax_002dDependent.html#Vax_002dDependent">Vax-Dependent</a> <hr><br> </div> <h4 class="subsection">9.34.6 VAX Operands</h4> <p><a name="index-VAX-operand-notation-1770"></a><a name="index-operand-notation_002c-VAX-1771"></a><a name="index-immediate-character_002c-VAX-1772"></a><a name="index-VAX-immediate-character-1773"></a>The immediate character is <span class="samp">$</span> for Unix compatibility, not <span class="samp">#</span> as DEC writes it. <p><a name="index-indirect-character_002c-VAX-1774"></a><a name="index-VAX-indirect-character-1775"></a>The indirect character is <span class="samp">*</span> for Unix compatibility, not <span class="samp">@</span> as DEC writes it. <p><a name="index-displacement-sizing-character_002c-VAX-1776"></a><a name="index-VAX-displacement-sizing-character-1777"></a>The displacement sizing character is <span class="samp">`</span> (an accent grave) for Unix compatibility, not <span class="samp">^</span> as DEC writes it. The letter preceding <span class="samp">`</span> may have either case. <span class="samp">G</span> is not understood, but all other letters (<code>b i l s w</code>) are understood. <p><a name="index-register-names_002c-VAX-1778"></a><a name="index-VAX-register-names-1779"></a>Register names understood are <code>r0 r1 r2 ... r15 ap fp sp pc</code>. Upper and lower case letters are equivalent. <p>For instance <pre class="smallexample"> tstb *w`$4(r5) </pre> <p>Any expression is permitted in an operand. Operands are comma separated. <!-- There is some bug to do with recognizing expressions --> <!-- in operands, but I forget what it is. It is --> <!-- a syntax clash because () is used as an address mode --> <!-- and to encapsulate sub-expressions. --> </body></html>